Reaction kinetics, mechanism, and product analysis of the iron catalytic graphitization of cellulose

Biomass based porous graphitic carbon are valuable materials in terms of renewable energy and environmental remediation; however, the catalytic graphitization mechanism of biomass and the solid char evolution process have not been comprehensively studied. Therefore, iron catalytic graphitization process of cellulose was investigated and the reaction kinetics, thermodynamics, pyrolytic behavior, and product properties analyzed in detail. It was found that iron addition lowered cellulose decomposition temperature, but higher average activation energy (230 kJ/mol), and higher entropy (100 J/mol). In-situ-produced Fe3C and Fe promoted secondary reactions and activated C-H bonds, which led to an increase in the production of hydrogen and solid char from 2.9 mmol/g to 8.1 mmol/g and 6.3 wt% to 19.9 wt%, respectively, at the expense of the liquid oil yield. Furthermore, the iron addition promoted the degree of graphitization and etched porosity. The intrinsic reaction kinetics, thermodynamics, and technical analysis reported herein may guide the application of bioenergy for the preparation of porous graphite and hydrogen.

Automated summary

The addition of iron was found to lower the decomposition temperature of cellulose, increase the production of hydrogen and solid char, and promote the formation of porous graphite.